height, weight = eval(input("请输入身高(米）和体重（公斤）[逗号隔开]："))
bmi = weight/ pow(height,2)
print("BMI 数值为：{:.2f}".format(bmi))
nat =""
if bmi < 18.5:
    nat ="偏瘦"
elif 18.5 <= bmi <24:
    nat ="正常"
elif 24 <= bmi <28:
    nat ="偏胖"
else:
    nat ="肥胖"
    print("国内BMI 指标为'{}'")